This is controlled by how your Active Directory group schema is configured. For example this is the group schema setup for me. Once groups are aggregated in SailPoint I have entitlement displayName set to msDS-PrincipalName which will be of format domain\displayName while value attribute for the ManagedAttribute is set to distinguishedName of the AD group
For your issue with roles please check how are your role profiles are configured. It should usually have the AD group DN which is the value of the entitlement (Managed Attribute)